The purpose of this study was to investigate fast-food consumption and it's nutrient density, and the correlation between subject's characteristics and consumption frequency of fast-foods among middle school students. The questionnaires were distributed to 150 male and 190 female students in Cheongju city. The data were analyzed using SAS and statistics used were percent of frequency, chi-test, t-test, and pearson's correlation coefficient. The main reasons for using fast-food restaurants were 'good taste' and 'convenience'. The major concerns when the subjects choose fast-foods were 'taste (65.9%), price (20.3%) and 'nutrition' (6.0%). The consumption pattern of fast-foods go as follows: twice a month (42.3%), once a week (31.5%), and less than once a week. The number of fast food items that the subjects ate for one meal was two (46.0%) or three (33.2%). The most frequently chosen combination of foods for number of two choices was beefburger and cola . The mean average energy intake from fast foods for one meal was 620.7 kcal for male, 504.5 kcal for female. The energy ratio of carbohydrate :protein :fat from fast foods was 49 :14 :43, which means fat intake is much higher than recommended level (20%). Fiber was appeared to be the lowest on the nutrient density which was 17.7% of the recommended level for Koreans, vitamin C was next (22.8% for male, 20.7% for female). In mineral, iron was the lowest (71.8% for male, 67.1% for female), and protein was over 100% for both males and females. Frequency of fast food intake was positively correlated with eating frequency of the salty, the sweets, ham, caffeine containing foods, instant noodles, and cookies. In conclusion, frequent consumption of fast foods can lead unbalanced nutrient intakes for middle school students, and those who consumed fast foods frequently showed undesirable food habits in their daily meal. Therefore, nutrition education for middle school students should be needed to encourage them to choose more nutritious food and have healthier dietary pattern.